Phase II study of intravenous CCNU in colorectal adenocarcinoma was undertaken. No forming toxicity was hematologic suppression at the 100-130 mg/M2 level. Many patients developed chills, fever, nausea, vomiting, dyspnea, and hypoxia after therapy. Of 13 evaluable patients, two patients have shown partial remission and one patient a probable partial remission. Three patients showed lesser responses or stabilized from previously advancing disease. Seven patients showed progression of disease. Three patients are inevaluable at present because of recent therapy. This drug appears to have some degree of efficacy in colorectal adenocarcinoma.